SUNSET: 
B612 Debuts Its Asteroid-Seeking Sentinel
Astronomers warn that it's not a question of "if" Earth will be hit by an asteroid, but "when." If a private group of space veterans has its way, a Sun-orbiting spacecraft will find threatening objects decades before they can strike us.
Titan's Tropical "Oases"
With a surface temperature hundreds of degrees below zero, Saturn's biggest moon is hardly a vacation paradise. But new Cassini results suggest that future visitors might be able to splash around in some liquid-methane lakes near Titan's equator.
NASA’s New Spy Scopes
Out of the blue, NASA finds itself the new owner of two new Hubble-class space telescopes sitting in a warehouse, courtesy of a spy agency that didn't want them. But like many gifts, they aren't exactly free.
GALEX Gets New Lease on Life
NASA decided to shut down its Galaxy Evolution Explorer in Februrary. But now Caltech has stepped in with private funding to keep the mission going.
Dawn Confirms Vesta's Link to Meteorites
Spectral mapping by NASA's Dawn spacecraft has confirmed what planetary scientists have suspected for decades: hundreds of meteorites on Earth are rocks blasted from the surface of the second-largest asteroid.
Streaking Snowballs in Saturn's F Ring
Self-destructing clumps of ice particles are changing the face of Saturn's bizarre F ring. No longer unseen ghosts, these theoretically predicted objects are putting on quite a show for NASA's Cassini spacecraft.
Asteroid Mining for Fun and Profit
A cadre of space entrepreneurs has hatched a plan to identify thousands of small near-Earth asteroids — and then to exploit the mineral wealth that many of these space rocks are certain to contain.
WISE Identifies Mystery Sources
Astronomers are using infrared observations from NASA's WISE spacecraft to identify sources seen at energies a million times greater. The work may help astronomers figure out whether they've detected unknown cosmic phenomena.
Sky & Telescope's New Moon Globe
The year-long effort was time consuming and tedious, but S&T's staff is proud to unveil the first wholly new globe of the lunar surface in more than four decades.
Kepler Mission Gets Four More Years
NASA's incredibly successful planet-hunter has had its mission extended to 2016 — giving it extra time to find Earthlike worlds in Earthlike orbits.
Vesta: A Study in Black and White
NASA's Dawn spacecraft is scrutinizing the second-largest asteroid from close range. Yet some aspects of Vesta's surface — especially splashes of very bright and very dark material — are puzzling.
Hubble's Hidden Treasures Competition
Try your hand at creating a beautiful Hubble image and you might win an Apple iPod Touch or iPad.
March Madness on Mercury
After a full year of scrutiny by NASA's Messenger orbiter, the innermost planet is revealing itself to be unique — and downright confounding — to the project's scientists.
How Big is the Sun, Really?
By carefully recording the track of Mercury when it crossed the solar disk in 2003 and 2006, observers have measured the Sun's diameter more accurately than ever before.
Mars and Moon: Not Dead Yet?
The Martian and lunar surfaces were thought to be geologically dead. But twitches of recent activity are turning up in extreme closeups from orbiting spacecraft.
New Evidence for Ancient Martian Ocean
For decades planetary scientists have speculated about whether a huge depression that dominates the northern hemisphere of Mars was once flooded with water eons ago. Now radar soundings are showing that the answer might be "yes".
Show Your Support for Pluto's Probe
NASA's New Horizons spacecraft is now just 3½ years from its historic flyby of Pluto. Mission scientists have launched a petition to have the spacecraft commemorated on a U.S. postage stamp — and they want you to sign it!
Opportunity Takes a Bow, Gets Some Rest
It's been eight years since NASA dropped twin rovers onto the Martian surface. Spirit succumbed to the planet's harsh conditions in 2010, but Opportunity continues to amaze mission scientists with its longevity and scientific productivity.
Farewell to Rossi's Explorer
Last week, NASA engineers reluctantly shut down the Rossi X-ray Timing Explorer, a largely unheralded orbiting outpost that relayed a steady stream of observations for 16 years.
GRAIL's Twins Safely Reach the Moon
Braking rockets fired on cue yesterday and today, placing twin spacecraft in lunar orbit. In the coming months, they will exploit the Moon's own gravity to revolutionize what we know about the lunar interior.
